- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Tunable optical and magnetic properties of Ni-doped CuSe nanowires using AAO template assisted hydraulic method
摘要： High uniformity of un-doped and Ni-doped CuSe nanowires have been fabricated through smelting the bulk and injecting the melted liquid into the anodic aluminum oxide (AAO) template. The Ni dopant concentration and morphology of CuSe nanowires can be well controlled via preparing the bulk materials and the channel size of AAO template. The cathodoluminescence (CL) peaks of the un-doped, 0.5 at% and 1.0 at% Ni-doped CuSe nanowires showed a redshift of about 26 nm and 42 nm from un-doped CuSe nanowires (579 nm), respectively. Furthermore, above room temperature ferromagnetism was observed in 1.0 at% Ni-doped CuSe nanowires at 300 K. The facile injection molding method fabricated nanowires with tunable optical and magnetic properties could be applied to prepare varied nanomaterials for spintronic devices in the further.
关键词： optical,anodic aluminum oxide (AAO),CuSe,doped,nanowires,magnetic
更新于2025-11-14 17:03:37
-
In situ Photoluminescence Study of Plasma Effects on Passivation of Crystalline Silicon Coated with Aluminum Oxide
摘要： A degradation of crystalline silicon surface passivation provided by aluminum oxide (Al2O3) is generally observed after plasma processes, e.g., deposition of amorphous silicon nitride. To minimize such detrimental effect, a better understanding of the interaction between plasma species and the Al2O3 layer is required. Using in situ photoluminescence, the passivation quality of as-deposited and annealed crystalline silicon wafers coated with Al2O3 grown by atomic layer deposition is characterized in real time during argon-hydrogen plasma exposure. The photoluminescence intensity of as-deposited samples instantly steps up after the plasma ignition, and then it gradually decreases as a function of plasma exposure time. However, only degradation of photoluminescence signal can be found if the samples are annealed prior to the plasma treatment. The interaction between vacuum UV light from plasma and different types of chemical bonds in the Al2O3 layer is proposed to explain the obtained results. Understanding the mechanisms and root cause leading to different behavior between as-deposited and annealed samples under plasma exposure is a first step toward redesigning the process flow for better surface passivation.
关键词： in situ photoluminescence,plasma exposure,aluminum oxide,surface passivation
更新于2025-09-23 15:23:52
-
Fabrication of thin-film spherical anodic alumina oxide templates using a superimposed nano-micro structure
摘要： Compared to the single-scale planar anodic aluminum oxide (AAO) film, the multi-scale hierarchical AAO structures can have a better performance due to the larger surface area. The conventional multi-scale AAO structure on a micro-pattern surface was fabricated using time-consuming lithography and etching process at high cost. In this article, the 3D porous AAO films with nanopores of 35~45 nm in diameter have been achieved on the surface of silica micro beads of 2 μm in diameter. The superimposed nano-micro structure was fabricated using hybrid-pulse anodizing the sputtered Al film on beads with a period of negative potential to dissipate Joule heating at room temperature. The 3D AAO-on-beads structure provides a large-surface-area substrate for enhancing the sputtered TiO2 photocatalysis. The photocatalysis on the superimposed nano-micro structures can exhibit a high performance with the MB concentration of 30% after 15 hr photo-degradation.
关键词： AAO,nano-microstructures,anodic aluminum oxide,nanoporus alumina,micro bead
更新于2025-09-23 15:23:52
-
Sol-Gel Template Synthesis and Characterization of Lu2O3:Eu3+ Nanowire Arrays
摘要： Uniform Lu2O3:Eu3+ nanowire arrays were successfully prepared by the sol-gel process using anodic aluminum oxide (AAO) templates. The as-synthesized nanowires are homogeneous, highly ordered, and dense and have a uniform diameter of ~300 nm defined by the AAO templates. The X-ray diffraction and selected area electron diffraction results show that the Lu2O3:Eu3+ nanowires have a polycrystalline cubic structure, and the crystallite size of the Lu2O3:Eu3+ nanowires is confined by the AAO template. The nanowires within the AAO template showed good photoluminescence and X-ray-excited optical luminescence performances for Lu2O3:Eu3+. The emission peaks were attributed to the 5D0 → 7FJ transitions of Eu3+ (J = 0, 1, 2, 3).
关键词： sol-gel method,nanowire arrays,Lu2O3:Eu3+,anodic aluminum oxide (AAO)
更新于2025-09-23 15:23:52
-
Validation of the model of TSL isothermal decay in dosimetric α-Al2O3 crystals
摘要： New features of isothermal build-up of thermally stimulated luminescence (TSL) related to deep traps in anion-deficient alumina single crystals are revealed. It was found that the TSL build-up at 630-750 K depends on the structure of the glow curve and is associated with the presence of a high-temperature component with Tm=700 K. Isothermal TSL build-up for the peak at 573 K is well expressed in UV-irradiated samples and is very weak after sample irradiation by a pulsed electron beam. The TSL build-up for this peak is registered for the luminescence of F centres but is absent for the emission of F2+ centres and chromium ions. The obtained results confirm the validity of the kinetic model of the TSL build-up that takes into account the process of thermal ionization of the excited states of F centres in aluminum oxide.
关键词： TSL build-up,Deep traps,Thermal Ionization of F centres,Aluminum oxide,Thermally stimulated luminescence
更新于2025-09-23 15:22:29
-
Scalable fabrication of geometry-tunable self-aligned superlattice photonic crystals for spectrum-programmable light trapping
摘要： Superlattice photonic crystals (SPhCs) possess considerable potentials as building blocks for constructing high-performance devices because of their great flexibilities in optical manipulation. From the prospective of practical applications, scalable fabrication of SPhCs with large-area uniformity and precise geometrical controllability has been considered as one prerequisite but still remains a challenge. In this work, we developed an anodic aluminum oxide template-guided approach to realize Ni SPhCs with the maximum area (~500 mm2) ever reported. By virtue of the dual-pore self-alignment effect arising from the periodic anodization electric fields, uniform structures over large areas were obtained for Ni SPhCs. Meanwhile, the geometrical parameters for every array of nanopores in terms of pore depth, size, and morphology can be independently controlled due to the sequential pore-opening. Based on the experimental observation about the geometrical dependence of the light absorption for Ni dual-pore SPhCs, we further fabricated Ni SPhCs with simultaneously-shaped nanopores and nanoconcaves, which not only simplified the fabrication process but also achieved omnidirectional stably-strong (~95%) light absorption spectra. Optical simulations elucidated that surface plasmon resonance and cavity resonance are responsible for the strong light trapping. Notably, the fabrication technique is applicable to Ni SPhCs with different periodicities, leading to spectrally programmable light absorption spectra. With Ni SPhCs as solar absorber, the water evaporation efficiency of a solar steam generation system and the open circuit voltage of a solar thermoelectric generator demonstrated 2.3 and 2.5 times improvement, respectively.
关键词： geometrically tunable,surface plasmon resonance,self alignment,superlattice photonic crystal,cavity resonance,anodic aluminum oxide template
更新于2025-09-19 17:15:36
-
Charge-Transfer Character in Excimers of Perylenediimides Self-Assembled on Anodic Aluminum Oxide Membrane Walls
摘要： Chromophore aggregation strongly impacts the efficiency of organic photovoltaics (OPVs). Perylene-3,4:9,10-bis(dicarboximide) (PDI)-based electron acceptors have been shown to be excellent alternatives to fullerenes in OPVs, provided their supramolecular assemblies do not form excimers. In order to study this phenomenon in a controlled fashion, we have prepared two PDI derivatives that were incorporated into an anodic aluminum oxide (AAO) membrane. In one system, the PDI molecule has an n-propyl silatrane attached to one of its imide nitrogens, while a 12-tricosanyl group is attached to the other imide nitrogen. The silatrane reacts with the AAO surface to covalently bind the PDI. The other PDI has 12-tricosanyl groups on both imide nitrogens, which intercalate with n-octadecylsilane chains covalently bound to an AAO membrane. Since aluminum oxide is a wide bandgap semiconductor, photoexcitation of PDI does not result in charge injection into the AAO membrane; thus, the intrinsic electronic properties of the aggregated PDI molecules within the membrane can be studied. Both PDI derivatives form excimers upon photoexcitation with and without solvent in the AAO membrane pores which display increasing charge transfer character with increasing solvent polarity. Since the AAO membrane allows for any choice of solvent to be infiltrated into its pores, the PDI photophysics can be modulated over an arbitrary range of solvent polarities, irrespective of whether PDI is soluble in a particular solvent. The results presented here show how to tune the intermolecular interactions of PDI and related rylene dyes attached to walls of the AAO pores to understand the intermediate regime between solution and the solid state.
关键词： Excimers,Anodic aluminum oxide membrane,Perylene-3,4:9,10-bis(dicarboximide),Chromophore aggregation,Charge transfer character,Organic photovoltaics
更新于2025-09-19 17:13:59
-
Fabrication of gold nanorod arrays on a cylindrical surface of optical fibers by using in-situ electrodeposition
摘要： Optical fiber is an excellent light-coupled substrate, which has the characteristics of large a length-diameter ratio with a cylindrical surface. Recently, various methods have been reported in order to improve the ability of local optical fields. In particular, methods aimed to address the efficient coupling and optical resonances by modifying metal nanostructures on the light-coupled substrate have been developed. However, existing methods are largely applicable to planar or tip substrates, and it remains a significant challenge to prepare metal nanostructures on a cylindrical substrate. In this study, we proposed a novel strategy to fabricate gold nanorods arrays (AuNRs) by electrodepositing them in anodized aluminum oxide (AAO) templates on the cylindrical surface of optical fibers. Briefly, AAO templates were prepared in-situ by using a constant current density secondary oxidation method on the cylindrical surface of optical fibers, and then the AuNRs were in-situ deposited in the AAO templates by electrodeposition. The features of the AuNRs such as diameter, nanorod pitch, and height could be easily regulated by adjusting the parameters of electrodeposition and the anode oxidation. The SEM images demonstrates that AuNRs exhibit a satisfactory consistency with a uniform diameter and favorable self-supporting properties. The relationships between the current density, pore diameter and pore distribution were explored, combined with the voltage-time curve during anodic oxidation. Furthermore, the surface plasmon resonance (SPR) optical properties of the AuNRs on the cylindrical surface were analyzed using the Finite-difference Time-domain Algorithm (FDTD) method. Results suggest that this alternative in-situ electrodeposition strategy has the potentials to be applied to SPR optical fiber sensing.
关键词： Gold nanorods arrays,Finite-difference time-domain algorithm,In-situ electrodeposition,Cylindrical surface of optical fibers,Anodized aluminum oxide templates
更新于2025-09-19 17:13:59
-
Local atomic structure of the GaN-side of the Al2O3/GaN interface revealed by X-ray absorption spectroscopy
摘要： The interface between a gate insulator (Al2O3) and a semiconductor (GaN) was investigated via surface-sensitive Ga K-edge extended X-ray absorption fine structure spectroscopy, achieved by detecting the Ga LMM Auger electrons originated from the Ga K-shell absorption. This GaN-side interface study was conducted on Al2O3 thin films formed via atomic layer deposition. The determined atomic structures revealed GaN crystalline changes and the formation of Ga–O bonds due to nitrogen annealing.
关键词： Aluminum oxide (Al2O3),Interface,Post-deposition annealing (PDA),Gallium nitride (GaN),Extended X-ray absorption fine structure (EXAFS),Atomic layer deposition (ALD)
更新于2025-09-19 17:13:59
-
A Rapid, Label-free and Impedimetric DNA Sensor Based on PNA-modified Nanoporous Gold Electrode
摘要： A gold nanoparticle film was successfully prepared on highly ordered and porous anodic aluminum oxide substrate through thermal evaporation deposition technique. As-fabricated nanoporous gold electrode modified by thiol-derivative peptide nucleic acid (PNA) was applied for impedimetric DNA sensing. In-situ kinetic analysis of PNA/DNA hybridization process was realized by electrochemical impedance spectroscopy (EIS) method. Considering the special structure of nanoporous gold electrode, a new equivalent circuit model was proposed for EIS data fitting. The sensitivity of PNA-modified nanoporous gold electrode is 0.4 Ω/cm2·nM. Meanwhile, complementary DNA target could be detected at concentration as low as 10 nM, which indicating that a methodology for rapid, sensitive and label-free detection of DNA has been set-up based on nanoporous gold electrode.
关键词： DNA sensing,nanoporous gold electrode,peptide nucleic acid,anodic aluminum oxide
更新于2025-09-10 09:29:36